But the health care law was, ultimately, a pretext. This was a test case for the long-standing—but previously fringe—campaign to rewrite Congress' regulatory powers under the Commerce Clause.
By ruling that the individual mandate was permissible as a tax, he joined the Democratic appointees to uphold the law—while joining the Republican wing to gut the Commerce Clause (and push back against the necessary-and-proper clause as well).Here's the Chief Justice's opinion (italics in original):
Construing the Commerce Clause to permit Congress to regulate individuals preciselybecause they are doing nothing would open a new and potentially vast domain to congressional authority. Congress already possesses expansive power to regulate what people do. Upholding the Affordable Care Act under the Commerce Clause would give Congress the same license to regulate what people do not do. The Framers knew the difference between doing something and doing nothing. They gave Congress the power to regulate commerce, not to compel it. Ignoring that distinction would undermine the principle that the Federal Government is a government of limited and enumerated powers. The individual mandate thus cannot be sustained under Congress’s power to “regulate Commerce.”